Pharmacokinetics Flashcards
What is bioavailability?
The fraction of a drug that reaches the systemic circulation after oral dosing
Name three ways drugs get transported around the body
Protein binding
Blood flow
Lipid solubility
Where are drugs metabolised and excreted?
Metabolised in liver
Excreted in kidneys
What happens to lipid soluble drugs in the liver?
Converted to water soluble so can be excreted by adding a conjugate or modifying the drugs structure
Metabolism can deactivate or activate drugs. Explain
When a drug is metabolised to water soluble it’s effect and toxicity reduce.
But some drugs are coated and only becomes activated when metabolised by the liver.
What is a prodrug?
Only activated when it reaches the liver
Where are antivirals activated?
Their site of action
Drugs can affect the liver and it’s metabolism, name two ways
Inhibitors or inducers
What happens if you take an inhibitor drug along with a substrate ?
The substrate will have a heightened effect as the liver metabolism enzymes have been inhibited by the inhibitor drug
What is genetic polymorphism?
Some people do not have the enzymes to metabolise drugs so they have no effect
What types of drugs are filtered by glomerular filtration?
Unbound
How are free and bound drugs secreted?
Active secretion
What is passive reabsorption?
Drug is transferred back to blood usually from the intestines if it has been excreted by the liver into bile
In an overdose case, how would you make the excretion of a drug quicker?
Make the urine acidic
What is the renal clearance equation?
Rate of excretion / plasma concentration
